Brief Description of the Prior Art
Electrically powered ceiling fans are generally mounted to the ceiling of an enclosure in which the fan is to be employed, utilizing, in doing so, two different mounting methods. It has been necessary to manufacture and sell two different types of fans, each specifically adapted for installation by the use of a different method from that which is utilized in installing the other of the two types of fans.
In a room or other enclosure in which there is little head room due to a relatively low ceiling, it is usually desirable to employ flush mounting in securing the fan to the ceiling. A flush mounted fan is attached to the ceiling so that there is a relatively small space between the fan motor housing, and the blades carried thereby, and the ceiling. Although some sacrifice in efficiency is often experienced as a result of flush mounting of the fan so that the blades are nearer to the ceiling than is optimum, this type of mounting is necessary to enable the fan to be operated safely without danger of the blades striking persons in the room. Characteristically, flush mounted fans do not include a down rod, which is a usual subassembly employed in the second general catagory of fan which is adapted to be mounted to the ceiling in a different way.
Where down rod-suspended fans are employed, an elongated, veritcally extending down rod is utilized to interconnect the fan motor housing with a bracket by which the fan is secured to the ceiling. The down rod thus spaces the fan motor housing downwardly from six to twelve inches or more from the ceiling, and supports the fan motor housing and the fan blades at a location where a more efficient movement of the air is developed by the rotating blades. Generally, the down rod will be swivelly mounted in the canopy so that the assembly will accommodate some rocking or swaying motion of the fan housing and blades in the event slight unbalance should develop during usage, or the fan should be struck by some person or object therebelow.
It is believed that until the present time, a fan structure has not been proposed or offered which facilitates the optional installation of the fan in either a flush mode or a suspended down rod-type mounting, at the option of the purchaser. Such is very desirable because such a fan would not be limited in its installation to a particular size of room or ceiling height, and it would also facilitate placement transfer between rooms of a relatively high ceiling, and rooms of a relatively low ceiling, during its effective operating life.